/*******************************************************************************
 * Copyright (c) 2005, 2014 springside.github.io
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 *******************************************************************************/
package com.listening.framework.inteceptor;

import java.io.Serializable;

import javax.annotation.PostConstruct;

import org.apache.shiro.authc.AuthenticationException;
import org.apache.shiro.authc.AuthenticationInfo;
import org.apache.shiro.authc.AuthenticationToken;
import org.apache.shiro.authc.DisabledAccountException;
import org.apache.shiro.authc.SimpleAuthenticationInfo;
import org.apache.shiro.authc.UsernamePasswordToken;
import org.apache.shiro.authc.credential.HashedCredentialsMatcher;
import org.apache.shiro.authz.AuthorizationInfo;
import org.apache.shiro.realm.AuthorizingRealm;
import org.apache.shiro.subject.PrincipalCollection;
import org.apache.shiro.util.ByteSource;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.google.common.base.Objects;
import com.listening.framework.exception.BusinessException;
import com.listening.framework.utils.Encodes;
import com.listening.works.domain.common.UserDomain;
import com.listening.works.service.common.UserService;

public class ShiroDbRealm extends AuthorizingRealm {

	private Logger logger = LoggerFactory.getLogger(ShiroDbRealm.class);

	private UserService userService;

	public void setUserService(UserService userService) {
		this.userService = userService;
	}

	/**
	 * 认证回调函数,登录时调用.
	 */
	@Override
	protected AuthenticationInfo doGetAuthenticationInfo(AuthenticationToken authcToken) throws AuthenticationException {
		UsernamePasswordToken token = (UsernamePasswordToken) authcToken;

		UserDomain userDomain = null;
		try {
			userDomain = userService.selectByPK(token.getUsername());
		} catch (BusinessException e) {
			logger.error("查询用户信息异常", e);
			throw new DisabledAccountException("查询用户信息异常");
		}
		if (userDomain == null) {
			throw new DisabledAccountException("用户不存在");
		}

		if (!userDomain.IsEnable()) {
			throw new DisabledAccountException("不可用的用户名");
		}

		byte[] salt = Encodes.decodeHex(userDomain.getSalt());
		return new SimpleAuthenticationInfo(new ShiroUser(userDomain.getUserCode(), userDomain.getRealName()), userDomain.getPassword(),
				ByteSource.Util.bytes(salt), getName());

	}

	/**
	 * 授权查询回调函数, 进行鉴权但缓存中无用户的授权信息时调用.
	 */
	@Override
	protected AuthorizationInfo doGetAuthorizationInfo(PrincipalCollection principals) {
		ShiroUser shiroUser = (ShiroUser) principals.getPrimaryPrincipal();
		/*
		 * User user = accountService.findUserByLoginName(shiroUser.loginName);
		 * 
		 * SimpleAuthorizationInfo info = new SimpleAuthorizationInfo(); for
		 * (Role role : user.getRoleList()) { // 基于Role的权限信息
		 * info.addRole(role.getName()); // 基于Permission的权限信息
		 * info.addStringPermissions(role.getPermissionList()); } return info;
		 */
		return null;
	}

	/**
	 * 设定Password校验的Hash算法与迭代次数.
	 */
	@PostConstruct
	public void initCredentialsMatcher() {
		 HashedCredentialsMatcher matcher = new
		 HashedCredentialsMatcher(UserService.HASH_ALGORITHM);
		 matcher.setHashIterations(UserService.HASH_INTERATIONS);
		 setCredentialsMatcher(matcher);
	}

	/**
	 * 自定义Authentication对象，使得Subject除了携带用户的登录名外还可以携带更多信息.
	 */
	public static class ShiroUser implements Serializable {
		private static final long serialVersionUID = -1373760761780840081L;
		public String loginName;
		public String name;

		public ShiroUser(String loginName, String name) {
			this.loginName = loginName;
			this.name = name;
		}

		public String getName() {
			return name;
		}

		/**
		 * 本函数输出将作为默认的<shiro:principal/>输出.
		 */
		@Override
		public String toString() {
			return loginName;
		}

		/**
		 * 重载hashCode,只计算loginName;
		 */
		@Override
		public int hashCode() {
			return Objects.hashCode(loginName);
		}

		/**
		 * 重载equals,只计算loginName;
		 */
		@Override
		public boolean equals(Object obj) {
			if (this == obj) {
				return true;
			}
			if (obj == null) {
				return false;
			}
			if (getClass() != obj.getClass()) {
				return false;
			}
			ShiroUser other = (ShiroUser) obj;
			if (loginName == null) {
				if (other.loginName != null) {
					return false;
				}
			} else if (!loginName.equals(other.loginName)) {
				return false;
			}
			return true;
		}
	}
}
